Gear jumping back and forth since...

jeannot18

Removing the back wheel and refitting it. I received my new tyres and fitted them in. I always struggle to replace the back wheel into position. This morning I went to get my bike in the shed and the back tyre was flat. So i replaced the tube and during the ride the gears at the back were kind of jumping back and forth when I was going towards the bigger cogs. It never done it before so I take it that I messed up something when refitting the back wheel. Anything I should check/look for, or does the derailleur need some adjustment? Thanks
JC

supersonic

Either the wheel is not back in properly, or you need to readjust the gears.

jeannot18

supersonic wrote:

Either the wheel is not back in properly, or you need to readjust the gears.

Thanks Supersonic, the wheel is back in properly (i think :oops: ). So to adjust the gear do I do using the 2 little screw that are on the derailleur/cassette (??) the ones that move the gear shifter sideways, or do I use the wheel that tense the cable? I hope I make myself clear (just to add that the gear change ok, but then when I pedal I can feel the gear "jumping" back and forth maybe by a cog or 2)
Thanks
JC

Markmjh

firstly check that the wheel is sitting evenly in the dropouts, you may not need to adjust the gears

cooldad

And if the wheel is fine, adjust using the barrel adjusters on either mech or shifters.

jeannot18

Thanks guys will do that.

JC

getonyourbike

Also check if the mech is straight, ie. pointing straight down

Si1988

Sounds to me like your wheel was never seated properly in the first place, with my new bike I got my brother to sit on it before i tightened up the wheel, then sorted the gears out, only problem being my brother got a go on my bike before I did!

Given that if your wheel has been misaligned since new, I'd do a full re-calibration of your rear mech, just to be sure. Cant hurt to do this sort of thing once in a while anyway, as chains and cassettes wear over time.

jeannot18

Si1988 wrote:

Sounds to me like your wheel was never seated properly in the first place, with my new bike I got my brother to sit on it before i tightened up the wheel, then sorted the gears out, only problem being my brother got a go on my bike before I did!

Given that if your wheel has been misaligned since new, I'd do a full re-calibration of your rear mech, just to be sure. Cant hurt to do this sort of thing once in a while anyway, as chains and cassettes wear over time.

I did put my weight on when I refitted the wheel, and did not have the problem before that, the gear were changing perfectly, never jumping. It probably need some adjustment, I am due for a free service anyway so if I can't sort it myself I will take the bike in.
JC